Cut the Brussels sprouts crosswise on the stalk and cook for about 15 minutes in boiling salted water, drain and drain. Heat the oil in a non-stick pan and fry the potato noodles in it, turning until they are slightly brown. Add onion and Brussels sprouts and fry for another two minutes. Pour in the water, stir in the stock and season. Boil. Spread the cheese in pieces over it and bake with the lid for 2-3 minutes until the cheese has melted.